Baseplate holes: Number and Size?

[TheFuror]

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Originally posted by TheFuror:
The Napa (made by Wix) har much larger holes, albeit fewer of them. The K&N had their characteristic 1/4 inch inlet holes, and plenty of them.

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My mistake: upon re-inspection I saw that both of the filters I used (K&N HP-1007 and Napa Gold 1042) have the same number of inlet holes. The Napa filter has substantially larger inlet holes, however.

In my Avalanche, both filters produced virtually identical oil pressure readings.

Bob W.

 

[Gary Allan]

Okay ...here's a "field test" that showed me that for the most part ...the size and number of holes doesn't mean much (within limits).

In this post I described my sandwich adapter, a Perma Cool, in which I drilled two 13/64" holes since I had a very hard time believing Ralph that the very small 1/4" sprung poppet valve would be enough to feed the engine.

In that installation I got a warm filter. I still do ..until the oil gets below a certain viscosity and then it goes cold. The two 13/64" holes are more than enough to feed the ff filter and the rest of the engine. That is, those two small holes don't provide enough of a differential to sustain flow to the remote 1um filter. Warm when warm ...cool when hot.

Naturally there are some conditions and restrictions to this ...so this isn't a blanket assertion ..but it's proved to me that there is a rather broad range that holes in the filter can be in size and number before they effect oil flow/pressure (whichever you subscribe to).

 

[Lumberg]

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I suspect the flow rate is determined much more by the filter media and inner tube design than by the inlet holes.

Bob W. [/QB]

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Bingo

 

[Gary Allan]

I don't think either has a whole lot of impact. Velocity is the changing factor with intermediate restrictions. If the media can not allow enough velocity, the bypass opens. The flow virtually NEVER changes except when the relief valve in the pump opens. 5 gpm is 5 gpm whether it's a 20weight or a 50 weight ..whether it's a dense filter or a very pourous one ..whether it has small holes or big ones.

 

[TheLoneRanger]

I did calcuationslastyear that showed my Super Tech filter had less inlet area than outlet area. This concerned me until I thought about the big picture. The filter is only one part of the larger engine lube system. Considering this, the major restriction in the system has to be from the bearing clearances themselves. As long as the filter flows enough to feed the bearing system, then that should be good enough.

My point is that it takes a relatively low oil flow to feed the bearings and lifters,etc, and I suspect much of the excess pump output goes through the (pump) bypass anyway.....

 

[XS650]

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Originally posted by TheLoneRanger:
I did calcuationslastyear that showed my Super Tech filter had less inlet area than outlet area.

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Did you consider that the outlet screws over the spud on the engine so the effective outlet area is the inside of the spud on the engine.

As long as the area is about as big as the main oil passage in the engine, it won't make much difference.

 

[labman]

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Originally posted by XS650:

snip.... As long as the area is about as big as the main oil passage in the engine, it won't make much difference.

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Exactly

 

[TheLoneRanger]

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Did you consider that the outlet screws over the spud on the engine so the effective outlet area is the inside of the spud on the engine.

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Good point. I'm aware of this, but I can't honestly remember if I considered it when I did the figuring. If not, then that would explain the difference in area.

A curious thing I noticed on the ST, was that one inlet hole was larger than the rest. Anyone know why?

 

[XS650]

quote:

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Originally posted by TheLoneRanger:


A curious thing I noticed on the ST, was that one inlet hole was larger than the rest. Anyone know why?

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The answer is probably "why not"? That's not as smart assed as it sounds.

I can't think of any reason why they would go out of their way to make one of them a diferent size.

One possible reason is that one of the punches or dies on the gang punch that punches the holes had to be replaced and the only die/punch insert combination they had ready to stick in it was a different size.

There could be some other manufacturing expediency that caused them to do it.

There is a remote possibilty that they did it to be able to more easily index the base with relation to something else, but that would be a dumb design when thay can make the base so that it doesn't need to be indexed.

 

[T-Keith]

Almost all Champion filters have one hole larger then the others. It's their calling card.

 

[Gary Allan]

Keith, you would have been amused as I reached over to an ST16 as the thought cloud formed overhead "well we'll just see about that!" ...


sonovabeach ..you're right.

 

[TheLoneRanger]

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It's their calling card.

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I hadn't thought of that. Maybe since they pack lots of private labels, that's an easy to spot "proof of origin".....???

All ST's that I've ever bought (maybe a dozen), have had that off-sized hole.

 

[Filter guy]

The one larger inlet hole has been a Champ design for at least 30 years.

The reason for it has to do with orientation of the filter when silk screening ( painting) the brand name logo, part number , etc. onto the painted can.


It's not relivant for those filters which have a label put on them. But because Champ stamps out their own base plates, own their own tool and dies, it will continue to build filters with the one larger inlet hole for some time..